DE69732901T2 - METHOD AND SYSTEM FOR RECEIVING IN A TWO-WAY METERING SYSTEM - Google Patents

Description

Technical part

The The present invention relates to a method and a system to transfer of messages and also on a primary station and a secondary station for use in the system. An example of such a system is a feedback paging system, but it is likely It will be appreciated that the teachings of the present invention are directed to others Two-way messaging systems can be applied.

Background of the invention

Rear message paging systems have been described, for example, in WO96 / 14716. In an elementary form requires such a system that a paging network controller ("paging network controller "PNC) is provided to transmit a message to a predetermined address can be. The address receiving a call is capable of using a low power transmitter incorporated in the pager, to transmit a simple answer. The above-mentioned patent describes a system in which a Series of messages are transmitted to respective addresses and the PNC transmits invitations for the Addresses, their answers essentially simultaneously as pseudo-pleasing ones To transfer data sequences, which are scattered in the PNC and that the answers to the concerned Be sent, which requires the answer. In order to avoid, in the pagers power control techniques must be applied to to ensure, The PNC transmits responses from the PNC at comparable power levels the invitations with gradually increasing (or decreasing) Power levels and only those pagers that are capable of a relevant invitation of the transferred Receive invitations, transmit your answers. A feature of this known method is that relatively strict Control of the received power is required.

PCT Patent Application IB97 / 00492 describes a modification of the above Method, for the sake of convenience of description, rather than progressive Elimination is called. In this technique, the PNC transmits a series of messages about one Downlink to individually addressed pagers. The PNC transmits afterwards a control signal via the downlink that invites those pagers to make an uplink transmission would like, For example, a reply to a message, a service to apply or to submit a registration application to them in the To transmit substantially simultaneously as pseudorandom data sequences. The PNC analyzes those of the uplink transmissions, the understandable and then repeat the invitation, the confirmations these uplink transmissions includes, which were analyzed successfully, and consequently only those Pagers that responded the first time but received no confirmation have to try again.

in the Essentially, these known techniques demand that every pager stores a number of pseudorandom data sequences, each specific for one certain answer type. this leads to but to some rigidity when processing group messages which are individually stored on several messages and disassembled Messages react.

WO89 / 06407 describes a reconfirm paging system, where addresses are transferred to pagers in an ordered order will be followed by messages in a proper order transferred to the pagers and in response to it, various affirmations transmitted through the pagers distinguished by the use of a pseudo-choice code, referring to the order of transmission of the different ones Addresses and messages.

US-A-5 499 266 describes a confirmation paging system, with confirmations comprise a frequency-spanned transmission. All pagers use the same pseudo-random noise code to determine the frequency jumps, but confirmations from different pagers are by an explicit field in the confirmation distinguished.

Description of the invention

It is now u. a. an object of the present invention to provide more flexibility in the Operation of reply message systems introduce.

According to one aspect of the present invention, there is provided a method of operating a messaging system having at least one primary station that transmits over a downlink and a number of secondary stations making transmissions over an uplink, each of the secondary stations having its own address transmitted as part of a downlink message, characterized in that each uplink transmission has a pseudo-random data sequence generated by at least the address assigned to the secondary station is supplied to an n-bit sequence generator.

The transfers over the Uplink can Contain replies to messages sent via the downlink and / or applications for one Service.

To A second aspect of the present invention is a communication system provided with at least one primary station having means for performing transmissions over one Downlink and with a number of secondary stations with means for Carry out transmissions over an uplink, each of the secondary stations has its own address transmitted as part of a downlink message is characterized in that the means for performing transfers over the Uplink generate responses to messages, each of which Answers has a pseudo-random sequence of data resulting is generated that at least the address is supplied, the secondary station is assigned, namely to an n-bit sequence generator.

To A third aspect of the present invention is a secondary station adapted for use in a communication system, wherein at least a primary station News about transmits a downlink to addressed secondary stations, with each secondary station Has means for performing of transfers over one Uplink, characterized in that the means for carrying out transmissions over a Uplink are provided to in response to a received message a transmit pseudo-random data sequence, generated by providing at least one address that is the secondary station is assigned, namely to an n-bit sequence generator.

Short description of drawing

embodiments The invention are illustrated in the drawings and are in the present Case closer described. Show it:

1 a block diagram of a communication system,

2 a presentation of the transmission of invitation signals, the reception of CDMA answers and the analysis of the answers,

3 FIG. 4 is an illustration of the interlace effect of a pseudo-random data sequence response type of the system. FIG.

4A and 4B a representation of how confirmations are combined with an invitation signal transmitted via the downlink,

5 a block diagram of the PNC 10 .

6 a flowchart of the sequence of events,

7 a block diagram of a pager,

8th and 9 each a block diagram of an embodiment of a means for generating a pseudo-random data sequence,

10 an example of the sequence timing rules,

11 an example of a chip timing sequence,

12 a timing diagram for explaining the transfer of an invitation control sequence by the paging system and the transmission of a confirmation by a pager,

13 a timing diagram associated with the paging system that receives an acknowledgment that the user of a pager has played a message, and

14 and 15 Timing diagrams associated with the paging system receiving a response from a user of a pager.

In The drawings are the same for indicating corresponding elements Reference numerals.

Embodiments of the invention

In 1 the communication system comprises a paging network controller (PCN) 10 with a message input port 12 which receives pager addresses and associated messages from an operator provided with a PC or directly from a subscriber with a PC and a modem. The PNC 10 containing directories of information such as pager radio identity codes (RIC), areas to be served, frequencies, pager types, prevailing protocols such as POCSAG (or CCIR Radio Paging Code No 1) and ERMES, and the state of the pagers, collects the messages and their associated RICs along with other pertinent data packet information that goes to a paging area controller (PAC) 14 which formats the RICs and associated messages into a format provided by the base station transmitters (or transmitter portion of the base station transceiver). 16 with the help of a downlink to two-way pagers eighteen . 20 can be transferred.

If the two-way pager 20 identifies that a message is being transmitted that has its RIC, it receives the message and decodes it. Thereafter, when the user wishes to send a short answer using an integral keypad, he selects a pre-stored answer and when he returns from the PAC 16 invited to do so, he transmits his answer using an uplink. The response signals can be sent simultaneously as pseudo-random data sequences (PRDS).

There may be one or more receivers (or receivers of a transceiver) 22 to receive the replies and forward them to the PAC 14 in which it decodes and as data packets to the PNC 10 be supplied. The PNC 10 includes means for analyzing the signals and adjusting the responses to the messages transmitted via the downlink.

Those responses that are customized will be forwarded to the appropriate users in any suitable form, for example by e-mail or by transmission as one-way paging messages. Alternatively, the responses are applied to a message answering service operated by the paging network. In both cases, the respective two-way pager becomes 20 a confirmation sent. However, not all answers are adjusted because, for example, strong responses suffocate the weak responses as a result of the near-far effect. If the PNC 10 determining that only a small portion of the messages transmitted via the downlink have received responses, then it provides a general invitation to those pagers that did not respond to the messages or did not receive a confirmation to transmit their responses over the uplink to retransmit. The newly received answers are analyzed, where possible adapted and confirmations are transmitted. If it is determined that the total number of successful responses is still below a statistically determined threshold level, the cycle is repeated by transmitting a new invitation signal via the downlink. The process is repeated until either a predetermined number of cycles have been performed or the threshold level has been exceeded, and it is clear that no further understandable responses to the burst of messages are recoverable.

In the case of nearly simultaneously transmitted PRDS response signals, whenever a burst of response signals is received, those response signals that have been successfully analyzed will generally have the highest power levels at the antenna of the receiver 22 to have. In this way, when signals are removed from the accumulation of response signals when the next invitation signal is transmitted, signals from weaker sources, ie the pagers further away, are decoded and matched together. This sequence of events is referred to herein as "progressive elimination."

2 shows an example of a system in which answers contain PRDS signals that are transmitted simultaneously in response to an invitation signal via the downlink. In 2 Messages (not shown) have already been transmitted via the downlink. A first invitation INV1 is transmitted via the downlink. The pagers that have detected a message addressed to them respond to the invitation signal INV1 by transmitting a code sequence within a defined time slot RES1. A search routine SCH is triggered following the expiry of the time slot. In the search routine, codes appearing in the PNC 10 ( 1 ) are successively compared with the response data sequences and one after the other the responses to particular messages are identified. Because of the near / far problem, only the strongest response signals are detected and these are eliminated from the next search by acknowledgment signals transmitted via a downlink to inform pagers that were successful, not the subsequent invitation signals INV2 and INV3 react in the sequence.

It is expected that in a practical system the main part of the pager eighteen . 20 ( 1 ) at a certain distance from the antenna (s) of the receiver (s) 22 which means that they will have low power to the antenna. Accordingly, although, as illustrated, the duration of time slots RES1, RES2 and RES3 may be the same, it is preferred that variable slot lengths be assigned according to the expected number of responses, for example a small number of relatively high power responses and a large one Number of answers with a relatively low performance. Short slots are initially assigned such that the few strong powers can be efficiently eliminated with low interference and interference. Longer slots are then allocated to accommodate the low received powers contending with significant noise and interference levels.

If desired, the pagers eighteen . 20 have a power control on their transmitters so that the strength of their response signals can be varied in order to reduce the number of invitation / response cycles.

In a refinement of the basis of the 2 described embodiment shows 3 splitting the population of pagers into two groups and interlocking the transmission of messages and invitations for one group Pg1 over the downlink with the analysis of the responses over the uplink from the other group Gp2.

One Method of splitting the pager population is odd numbered pager of a group, say gp1, assign, and the even numbered pagers of a second group, say, Gp2 assigned. An alternative method is for the pagers the strength (RSSI) of the received downlink signal and by use a preset threshold to determine which one of us say two groups belong to them.

One method of providing an invitation message while simultaneously informing those pagers whose responses have been successfully analyzed is to place the messages M1 through M14 in an ordered sequence, as in FIG 4A presented, and in the invitation signal, 4B to send, providing a field FD with a corresponding number of time slots on a 1 to 1 basis, thus the slot 3 the message M3 corresponds. When the first invitation signal INV1 is transmitted, we say that all bits in field FD are zero, indicating that no responses have been received. But after the first round of analysis, acknowledgments are transmitted to, say, those pagers to which the messages M1, M3, M4, M9, M11 and M13 have been addressed by changing the bits in the slots 1 . 3 . 4 . 9 . 11 and 13 of field FD from "0" to "1". Other bits are changed as more messages are acknowledged.

The The number of cycles in which invitations are transferred can be one be fixed number. But if it is determined that the number succeeds decoded answers exceeds a statistically determined threshold, then further repetitions are terminated.

5 shows in block schematic form a PNV 10 who with a PAC 14 , a transmitter 16 the base station and a receiver 22 is coupled. The entrance port 12 is with a microcontroller 24 coupled with the directories 26 to 36 in terms of RICs, paging areas, frequencies, pager types, predominant protocols and the state are coupled. A message store 38 is with the microcontroller 24 coupled to storing messages when they are at the input port 12 be received. The memory 38 has an area 40 for storing information confirming that a response to a particular message has been received and confirmed. An exit 42 from the microcontroller 24 is with the PAC 14 coupled to provide data packets that must be formatted before being sent by the sender 16 be transmitted.

Answers by the recipient 22 are received via the PAC 14 to a signal analyzer 44 forwarded. If each answer is parsed successfully, it will match up with the messages in the store 38 to the microcontroller 24 forwarded. Once they have been brought together, the microcontroller arranges for a confirmation to be transmitted if that next invitation signal is sent via the downlink. At that point in time, the recipients of the replies are informed, for example by e-mail or by a one-way paging message, or the responses are stored together with the pager number concerned so that a subscriber can poll the memory as they wish. If the microcontroller 24 Once it has decided that all responses have been received for all practical purposes, it clears the messages in the message store in readiness to receive further messages via the input port 12 , In a more convenient way, the memory can 38 contain two halves, with one half processing the acknowledgments of the messages already sent via the downlink and the other half storing messages that still need to be sent.

6 Figure 12 is a flow chart showing the sequence of operations involved in transmitting messages, receiving responses, and confirming responses. The block 50 represents the start. The block 52 refers to the transmission of a sequence of messages and this block is followed by the block 54 with the transmission of an invitation signal. The block 56 refers to the reception of the PRDS responses, which are then analyzed and summarized with their respective messages, Block 58 , The block 60 refers to the transfer of confirmations. In the block 62 is checked to see if the number of successful responses exceeds a threshold indicating that as many responses as possible have been received. If the answer is No (N), the flowchart moves to the block 64 in which it is checked whether the predetermined maximum number of invitations has been reached. If the answer is No (N), the flow chart returns to the block 54 back. An affirmative (Y) answer from the blocks 62 and 64 ensures that the flowchart to the block 52 returns and the cycle is repeated.

In 7 includes the pager 20 a receiver 68 that with a decoder 70 which in turn is connected to a control processor 72 is coupled. The processor 72 works according to one in a read-only memory 74 stored program. The processor also includes an address memory (not shown) containing the unique address of this pager. In the event the pager receives a message, it will be in memory 76 saved with any access. The messages can then be displayed on an LCD display 80 be reproduced, their associated driver circuit 78 with the control controller 72 is coupled. Annunciator arrangements that include an acoustic transducer 82 , a light emitting transducer 84 and a vibrator 86 may be with the control processor 72 coupled. A keypad 88 provides a man-machine interface whereby a user may instruct the processor to perform multiple functions, such as a stored message on the display device 80 play. A transmitter 90 is with an output of the processor 72 as well as with an antenna 92 coupled. A receiver power control stage 94 is between the processor 72 and the receiver 68 provided for the practical battery conservation according to the provisions of the paging protocol to be followed. In the event that the pager transmits response signals as PRDS signals, the control processor comprises 72 Means for determining the sequence to be transmitted, taking into account the identity of the pager and / or the information in the original downlink message. The PRDS is then forwarded to the transmitter 90 passed on. If as an option power control on the transmitter 90 is to be applied, then by the processor 72 via a control line 96 a power control signal is provided.

Farther include the over transmitted the uplink Signals also requests for services, like registration, and in the appropriate way is the present one Invention also to the processing of such applications for services applicable in the same way as an answer, except that there is no match with an outgoing message.

The method of determining the uplink PRDS allows greater flexibility to be obtained when responding to downlink messages. In 8th a response PRDS is generated using two linear feedback shift registers 12 taps 100 . 102 and a 6-tap linear feedback shift register 104 whose outputs become an EXCLUSIVE-OR gate 106 (XOR). Each shift register includes an n bit XOR mask 108 . 110 . 112 and an n-bit shift register 114 . 116 . 118 where n = 12 is for sequence generators 100 . 102 and n = 6 for the sequence generator 104 , All sequence generators 100 . 102 . 104 are clocked simultaneously.

9 Figure 14 shows an example of an n-bit sequence generator, which is known per se and thus will not be described in detail here.

In the present example, the default parameters are h _a , h _b and h _{c of} the masks 108 . 112 respectively. 110 : 829 _h , 30 _h or B64 _h , and those of the shift registers 114 . 118 and 116 Namely, q, b and c are 001 _h, ([X] DIV2 ^N) DIV2 ¹² and ([X] DIV2 ^N) MOD2 ^12, wherein the subscript "h" in hexadecimal is, [X] refers in the POC -SAG standard to the 21 bit address and frame of the RIC of the pager and [N] is a constant defined by the operator between 3 to 7 inclusive. The default phase is given by (2 ¹² DIV2 ^N ) × ([X] MOD2 ^N ) certainly. In the following description, the following parameters are required along with their default values for the pager.

They are explained in detail in the following description:
Phase Step: 8
Transmission: released

In front the transmission, Pagers should bring the sequence generator into the given phase. It should be noted that phase zero of a sequence, such as initially charged, corresponds. Phase n is achieved by: the registers are clocked n times. If controlled, the Pager use different parameters.

It should be noted that the parameters 'h _a ', 'h _b ' and 'h _c ' define the PN family. All pagers in a given system should use the same family. Parameters 'b' and 'c' define the code sequence. A response code refers to the sequence as well as the phase.

• i. Pager antworten nur nach Empfang einer Einladungssteuersequenz ICS
• ii. Die Übertragungssequenz soll an dem Punkt starten, wo der Anfang des zweiten Synchronisationscodewortes, der dem Ende der Einladungsnachricht folgt, fällig ist. Beispiele davon sind in 10 dargestellt.
• iii. Das erste Bit der Übertragungssequenz soll beginnen, wenn das erste Bit des Synchronisationscodewortes beginnt, wie in 11 dargestellt. Die Toleranz dafür soll ± 100 μs sein.
• iv. Übertragungslänge wird durch die Einladungsbefehlssequenz bestimmt. Die Register werden L mal getaktet, wobei L durch den [Länge] Parameter in der Einladungssteuersequenz spezifiziert wird.
• v. Die Chip-Rate der Codesequenz soll 9600 Chips/Sekunde mit einer Toleranz von 10 ppm sein.

If transmission is required, the sequence generator is clocked to generate the chip sequence. The timing at which pacing is required to start should conform to the following rules:

• i. Pagers respond only upon receipt of an invitation control sequence ICS
• ii. The transmission sequence is to start at the point where the beginning of the second synchronization code word following the end of the invitation message is due. Examples of this are in 10 shown.
• iii. The first bit of the transfer sequence should begin when the first bit of the synchronization codeword starts, as in 11 shown. The tolerance for this should be ± 100 μs.
• iv. Transmission length is determined by the invitation command sequence. The registers are clocked L times, where L is specified by the [length] parameter in the invitation control sequence.
• v. The chip rate of the code sequence should be 9600 chips / second with a tolerance of 10 ppm.

In front modulation the filtered chip sequence is to be filtered in such a way that the total interference in the adjacent 25 kHz channel is -50 dBc is.

below Two-way command sequences are described.

The basics are the following:
Pagers transmit only in response to an invitation sent by the sending PNC system. More than one pager can transmit at the same time, as each pager uses a different sequence. Pagers do not need to be preprogrammed with special feedback channel RICs or other information.

pager use control sequences written in POCSAG (or CCIR Radiopaging Code No 1) Messages are embedded to determine how and when to be answered. Control sequences are considered part of a normal Text message fed to the user and some can to be sent as a special pager message in itself.

Characters are defined in one of two ways as follows:
<Value _h >: ASII characters in hexadecimal format. The valid range is from <00 _h > to <7F _h >.

"Character": ASCII characters like played.

For example, define "A" and <41 _h> the same character. It should be noted that according to the POCSAG standard, the least significant bit of each character is transmitted first.

Control characters are any characters from <00 _h > up to and including <1F _h > and <7F _h >. Printable characters are any other characters.

The Table 1 summarizes the control sequences and these commands become then defined in detail. Control sequences that are not flawless or sequences that are not properly structured are, must be ignored by the pager.

It It should be noted that of these sequences only three pieces (the Invitation, the answer point and the quick invitation control sequences) for one efficient two-way communication are essential. All other control sequences provide several improvements. For operators, the only automatic confirmations want to implement only the fast invitation control sequence is required.

Table 1: Forward channel response control sequence

The Invitation Control Sequence ICS defines how a pager should respond. The ICS can be a single pager or a group of pagers be sent. The ICS is used together with the response allocation control sequence RACS used.

A fast invitation control sequence FICS can be sent instead of a RACS / ICS pair.

pager immediately send an answer.

The invitation control sequence ICS defines the following for the pager:
The type of answers allowed.
A reference parameter.
A slot number used when implementing the progressive elimination technique described above.

The following are optional parameters:
The length of time that pagers should transmit.
A timestamp

Some Acknowledge bits. When progressive elimination is used, pagers use them Bits to determine if their transmission was received, and whether a retransmission is required.

• Wenn Bit 5 gesetzt ist: erforderliche Antworteinladung Bit 0 Bestätigungen. Wenn dieses (am wenigsten signifikante) Bit gesetzt ist, kann der Pager eine Bestätigungsantwort senden. Bit 1 Wiedergegebene Antworten. Wenn dieses Bit gesetzt wird, kann der Pager eine wiedergegebene Antwort senden. Bit 2 Benutzerantwort fertig Reaktion auf eine spezifische Nachricht. Wenn dieses Bit gesetzt wird, kann der Pager eine spezifische Benutzerantwort fertig Reaktion senden. Bit. 3 Benutzerantwort fertig Reaktion auf jede beliebige Nachricht. Wenn dieses Bit gesetzt wird, kann der Pager eine allgemeine Benutzerantwort fertig Reaktion senden. Bit 4 Benutzerantwortreaktionen. Wenn dieses Bit gesetzt wird, kann der Pager aktuelle Antworten auf eine Nachricht senden.
• Wenn Bit 5 deutlich ist. Unerbetene Antworteinladung Bits 0 bis 4 Unerbetene Antwortnummer (URN), wobei die Bits 0 bis 4 eine 5 Bit Nummer zwischen 0 bis einschließlich 31 definieren.

The invitation control sequence ICS has the following format:
<1E _h >'1' [Type] [RefICS] [Slot] {[Length]} {[Time]} {[REC]}
In which
[Type] defines which type of response from pagers is allowed and which optional parameters should be used. [Type] can be a value between <20 _h > up to and including <5F _h >. This should be interpreted as a 6 bit number as follows:

• If bit 5 is set: required response request bit 0 acknowledgments. When this (least significant) bit is set, the pager can send a confirmation response. Bit 1 Replied answers. When this bit is set, the pager can send a replayed response. Bit 2 user response ready response to a specific message. When this bit is set, the pager can send a specific user response ready response. Bit. 3 user response ready response to any message. When this bit is set, the pager can send a general user response ready response. Bit 4 User Responses. When this bit is set, the pager can send actual responses to a message.
• If bit 5 is clear. Unsolicited Response Invocation Bits 0 to 4 Unsolicited Response Number (URN), with bits 0 through 4 defining a 5 bit number between 0 through 31 inclusive.

Requested and unsolicited answers are described below.

[RefICS] Defines a unique identity to the invitation. [RefICS] is a single character that can have one of 95 values between <20 _h > and <7E _h >. This makes it possible for pagers to keep track with ranks and with associated invitation control ICs.

pager can only confirmations to send a message if [RefICS] matches [RefRACS] in the RACS. For others Types of responses to a message are in the [Time] parameter in the response allocation control sequence RACS specifies a time limit.

[Slot] This is used to implement the progressive elimination, and defines the invitation control sequences ICSen of the series. [Slot] is a single character between 30 _h and 3F _h inclusive. The value is determined from the least significant 4 bits. If progressive elimination is not applied, then it always contains 0 (<30 _h >).

{[Length]} A parameter that does not exist when [Type] < _20h >. Defines the number of times that the sequence generator in the pager should be clocked, L, as follows:
Bit 4 and bit 5 set: L = 2 ^N , where N is a number between 0 and 15, defined by bits 0 through 3.
Bit 4 free, bit 5 set: L = 3 × 2 ^N.
Bit 4 set, bit 5 free: L = 5 × 2 ^N.
Bit 4 and Bit 5 Free: L = 75 × 2 ^N.

{[Time]} A parameter that does not exist when [Type] is < _20h > or < _21h >. It contains 3 characters with the following format: dhm; d has one of 31 daily values from 1 to 31; h has one of 24 hourly values from 0 to 23; m has one of 60 minute values from 0 to 59; In all cases, these values are determined from the least significant 6 bits of the transmitted character, using characters between <20 _h> and <5F _h>. He defines the current time. Alternatively, use pagers when [Time] 'i'(<69_h>) is its own internal clock to determine the current time.

{[REC]} This parameter is not present when [Slot] is 0 (< _30h >). It contains detection bits that inform pagers that responses have been received by the paging system. The use of this parameter will be described later.

This Command must complete the message.

The Response Assignment Code Sequence RACS is always in a message embedded and defines a message if this one Answer required. It can become a single pager or a group be sent by pagers. It should be noted that pager only then send a response when an ICS has been received.

The Ensure definition of ICS and RACS as individual control sequences, if necessary, a number of pagers transmit their answers simultaneously.

The RACS defines the following for the pager:
A type parameter. This limits the type of responses allowed for the message and defines which possible parameters should be used.

Below are optional parameters:
A reference parameter. This is used in conjunction with the reference parameter in the ICS.

A Timestamp to limit non-acknowledgment responses.

The assigned response bit ARB is used for the current message become.

This is used to implement a progressive elimination and is used in conjunction with the [REC] parameter in the ICS, allow a pager the opportunity has to determine if an answer is needed or if a previous answer was received.

A Time stamping for the ARB

One Reply code for use for the message.

The response allocation code sequence RACS has the following format:
<1E _h >'T' [Type] {[RefRACS]} {[Time]} {[ARB]} {[TimeARB]} {[Code]}

[Type] Limits pagers so that only a subset of answers to the message can be given. [Type] is only a single character, which can have a value between <20 _h > and <5F _h >. It should be interpreted as a 6 bit number as follows:
Bit 0 confirmations. When this (least significant) bit is set, the pager can send an ACK response to the message.
Bit 1 Replied answers. When this bit is set, the pager can send a DISP response to this message.
Bit 2 user response ready response to a specific message. When this bit is set, the pager can send ANR, FLG, or ANSn responses to this message.
Bit 3 Assignment REC Bit. When set, [ARB] is included in the RACS.
Bit 4 Separate time-out for ARB. If set, [TimeARB] is included in the RACS. It can only be sent if bit 3 is set.
Bit 5 code present. If set, [code] is included in the RACS.

{[RefRACS]} A parameter that exists only when bit 0 of [Type] is set. He defines a unique identity for the answer. It is a single character that can have one of 95 values between <20 _h > and <7E _h >.

pager can only confirmations transmit a message, if [RefRACS] matches [RefICS] in the ICS. For others Types of responses to a message are those in the [Time] parameter specified time limit used. {[Time]} One parameter, the for Pager transmissions, the no confirmations are, set a time limit. This parameter does not exist if both bits 1 and 2 of the [Time] parameter are empty.

reply can not on news outside this time limit will be sent. The time limit will be on one of two ways specified - by using a time marker, or by using the pager's internal clock.

If a time stamp is used, [Time] is identical in format to the ICS [Time] parameter. The content is the current time, plus the required invitation window. Answers can only be given on messages when the ICS [Time] parameter is less than that in [Tome].

If the pager's internal clock is to be used, then [Time] is a single character from <60 _h > to <7E _h >. Responses can only be given to the message for the next [Time] with the following meanings: <60 _h > to <6F _h > Time limit in minutes using the least significant 4 bits; <70 _h > 30 minutes; <71 _h > 60 minutes; <72 _h > 120 minutes; <73 _h > 180 minutes; <74 _h > 360 minutes; <75 _h > 12 hours; <76 _h > 24 hours; all other values are occupied.

For example, if [Time] is 'e'(<65 _h >), then pagers can only send responses to messages in the next 5 minutes.

If [Time] 'JF!'(<4A_h><46_{h> <21h>)} is, pager can only send replies to messages when the ICS includes a time stamp before 0633 on the 10th of the month.

{[ARB]} This parameter is only available if bit 3 of [Type] is set and defines a REC bit for the pager. For calls to this pager: This parameter contains two hexadecimal characters, each with a value between '0' and '9', 'A' and 'F'. Together they form a two digit hexadecimal number in the range of '00' to 'FF'. For calls to a group of pagers: This parameter contains three characters 'Gn ₁ n ₂ ', where n ₁ n _{2 are} two hexadecimal characters, each one between '0' and '9', 'A' and 'F' to have. Together they form a two-digit hexadecimal number in the range "00" to "FF". Alternatively, they may contain a single "L" character. This instructs the pagers to use the previous value of [ARB].

{[TimeARB]} This parameter is only available if bit 4 of the [Type] is set. The format of the content of this parameter is identical to that in [Time]. It sets the time limit that applies to [ARB]. If this parameter does not exist:
If [Time] exists, it defines the time limit that applies to [ARB].

Otherwise [ARB] applies only when [RefRACS] with [RefICS] in the invitation control sequence ICS matches.

{[Code]} This parameter is only present if bit 5 of [Type] is set is. This parameter defines the pager for all responses only code to use on this message. He can take the provisional Sequence allocation control sequence TSACS and the provisional phase allocation control sequence TPACS are used.

[Code] contains 2, 3 or 5 characters, formatted as follows: 2 characters [Phase] 3 characters [Init b] [Init c] 5 characters [Init b] [Init c] [Phase] In which
[Init b] Contains a single character. The least significant 6 bits define the "b" 6 bit trigger. Bit 7 is ignored and can have any value.
[Init c] Contains two characters. The least significant 6 bits of each character together define the "c" 12 bit trigger. The first character of the two characters contains the most significant 6 bits, the second character the least significant bit. In the two characters, bit 7 is ignored and can have any value.
[Phase] Contains two characters. The least significant 6 bits of each character together define a 12 bit number between 0 and 4095. The first of the two characters contains the most significant 6 bits, the second the least significant bit. In the two characters, bit 7 is ignored and can have any value.

This Command requires a delimiter because the length of the RACS is unknown is.

The fast invitation control sequence FICS is a combination of invitation control sequence ICS and the response allocation control sequence RACS and may be a single Pager, or a group of pagers. Pagers can be instant to send a reply.

The FICS has the following format:
<1E _h >'F' [Length]
Where [Length] is the same as in the ICS command.

It should be noted that FICS is equivalent to the following ICS and RACS:
<IE _h >'I'<21 _h > [Ref] <30 _h > [Length] <1E _h >'T'<41 _h > [Ref]
Where [Ref] is any character. It is limited to only acknowledgment responses and can not be used to implement progressive elimination.

This Command does not require a delimiter, as the length of the FICS is known.

The Embedded response control sequence (EACS) is used to create a Users the opportunity too offer to give an answer to a message. The EACS can only in the same message as the RACS are sent and valid only for These news.

It Two forms of an embedded response are supported. In In the first form, real answer messages are embedded sent in the message. In the second form is a previously defined dictionary of answers specified. In this case, only a single EACS transmitted in the message become.

These Have to shape to be used exclusively. A message can be an EACS of any shape but can not contain an EACS of the two forms.

In the first form, the EACS has the following format:
<1E _h >'R' [Answer]
[Answer] Is any series that uses printable characters. Characters that are not in the range <20 _h > to <7E _h > are not allowed.

This Command is limited to the control character of a command that follow can (for example, another EACS, or an EOC), or the end the message.

One or more EACS of this form can be sent in the message. Upon receiving such a message, the pager will advise the user to dial a reply. There is also an additional included EACS. This is not sent by the paging system, but if desired can be selected by the user as an answer. This should be:
"None of these"

For example, a message can be:
Can we meet at McDonalds tonight?
<1E _h> R6pm <1E _h> R7pm <1E _h> R8pm <1E _h> RNO <1E _h> R I'll call you later.

Upon receiving such a message, the pager will inform the user to choose a response from:
6pm
7pm
8pm
No
I will call you later
None of these answers

In the second form, "can responses" previously stored in a pager can be used. Only one EACS can be sent in the message with the format below:
<1E _h >'rx'
Where x is a single hexadecimal number between "0" and "9", "A" and "F".

This identifies one of 16 "dose response dictionaries" in the pager. It be noted that dictionaries each any length up to 256 inputs. "Canned answer dictionaries" are optional, and as much as required by the operator.

Of the Command in this form does not require a delimiter, since the length is known is.

The Recovery default allocation control sequence RDACS is used to restore the default feedback masks, the triggers, and the phases used by the pager. She can be personal Messages as well as in group messages. This Command removes the effects of PPFACS, PSACS and PPACS.

The RDACS can be sent at any time, but must be sent in a message containing the RACS. This allows the paging system to determine if the RDACS was received correctly.

The RDACS has the following format:
<1E _h >'D'

And has no parameters. This command does not need a delimiter because the length the RDACS is known.

The End of command (EOC) control sequence can be in any Message be sent as delimiter to the mark of the end a control sequence, if necessary. It should be noted that each other any control characters or the end of the message also End of a control sequence marked.

The EOC has the following format:
<1 _h >'E'
And has no parameters.

The provisional sequence allocation control sequence TSACS may be in personal Messages as well as in group messages. The TSACS can only be in the same message as the RACS that does not have the [code] Contains parameters, be sent and only applies to Answers to this message.

The TSACS has the following format:
<1E _h >'x' [Init b] [Init c]
[Init b] Contains a single character. The least significant 6 bits define the 'b' 6 bit trigger. Bit 7 is ignored and can have any value.
[Init c] Contains two characters. The least significant 6 bits of each character together define the 'c' 12 bit trigger. The first character of the two characters contains the most significant 6 bits, the second character contains the least significant bit. In the two characters, bit 7 is ignored and can have any value.

It Note that when TSACS is sent as a group call, the Sequence and the phase to be set provisionally, which afterwards even closer is described.

The Provisional phase assignment control sequence TPACS can only be added to the unique RIC of a pager can be sent and can not be considered Group call to be sent. It is used to pick up the The default phase used by the pager. The TPACS can only be in the same Message like the RACS that does not contain the [code] parameter sent are and only applies to Answers to this message.

The TPACS has the following format:
<1E _h >'z' [phase]
[Phase] Contains two characters. The least significant 6 bits of each character together define a 12 bit number between 0 and 4095. The first character of the two characters contains the most significant 6 bits, the second character contains the least significant bit. In the two characters, bit 7 is ignored and can have any value.

The Phase of a sequence that uses a pager should be [phase]. The use of this parameter will be related later Table 2 described.

This Command does not require a delimiter because the length of the TPACS is known.

The transmit enable / disable command sequence (TEICS) may be sent to block or enable transmission from the pager. The TEICS has the following format: <1E _h >'A' Lock <1E _h >'a' Sharing

This Command changes the transmission parameter in the pager. If released, send k. When locked, pagers can do not send and you can only work as a one-way pager.

This Command does not require a delimiter because the length of the TEICS is known.

The permanent P.N. Family Assignment Control (PPFACS) can only can be sent to the unique RIC of a pager, and can not be sent as a group call. It is used to restore the default XOR feedback masks, which are used by the sequence generator.

The PPFACS can only be sent in the same message as the RACS, which does not contain the [Code] parameter, and applies to it and all subsequent messages.

All Pagers in a paging system should use the same family. This Command should be sent to pagers that are passing by use another family of presets.

The PPFACS has the following format:
<1E _h >'P' [Mask h _a ] [Mask h _b ] [Mask h _c ]
[Mask h _a ] Contains two characters. The least significant 6 bits of each character together define the 'h _a ' 12 bit feedback mask 108 (Please refer 8th ). The first character of the two characters contains the most significant 6 bits, the second character contains the least significant bit. In the two characters, bit 7 is ignored and can have any value.
[Mask h _b ] Contains a single character. The least significant 6 bits define the 'h _b ' 6 bit feedback mask 112 ( 8th ). Bit 7 is ignored and can have any value.
[Mask h _c ] Contains two characters. The least significant 6 bits of each character together define the 'h _c ' 12 bit feedback mask 110 ( 8th ). The first character of the two characters contains the most significant 6 bits, the second character contains the least significant bit. In the two characters, bit 7 is ignored and can have any value.

This Command does not require a delimiter because the length of the PPFACS is known.

The provisional P.N. Family allocation control sequence TPFACS can only can not be sent to the unique RIC of a pager be sent as a group call. It is used to restore the default XOR feedback masks, which are used by the sequence generator. The TPFACS can only in the same message as the RACS are not sent contains the [code] parameter and only applies to Answers to this message.

The TPFACS has the following format:
<1E _h >'Q' [Mask h _a ] [Mask h _b ] [Mask h _c ]
where the parameters are as above for the PPFACS. This command does not require a delimiter because the length of the TPFACS is known.

The permanent sequence allocation control sequence PSACS can only do this unique RIC of a pager can be sent and can not be considered Group call to be sent. It is used to restore the Voga sequence register used by the pager. The PSACS can only be sent in the same message as the RACS, which does not contain the [Code] parameter and applies to it and all subsequent messages.

The PSACS has the following format:
<1E _h >'W' [Init b] [Init c]
where the parameters are as described for the TSACS.

This Command does not require a delimiter because the length of the PSACS is known.

The permanent phase assignment control sequence PPACS can only be unique RIC of a pager can be sent and can not as a group call be sent. It is used to recover the from The default phase used by the pager. The PPACS can only be in the same Notice how the RACS are sent, not the [code] parameter contains and is valid for this and all subsequent news.

The PPACS has the following format:
<1E _h >'Y' [phase]
[Phase] Contains two characters. The least significant 6 bits of each character together define a 12 bit number between 0 and 4095. The first character of the two characters contains the most significant 6 bits, the second character contains the least significant bit. In the two characters, bit 7 is ignored and can have any value.

This Command does not require a delimiter because the length of the PPACS is known.

The Phase step definition sequence PSDCS defines the phase step between allowed codes. She would typically used for reprogramming pagers around.

The PSDCS has the following format:
<1E _h >'S' [Phase Step]
in which
[Phase Step] Contains a single character that can have any value. The least significant 6 bits define the phase step used by the pager. Bit 7 is ignored and can have any value.

This Command does not require a delimiter because the length of the PSDCS is known.

In some cases There may be a request for a control character as a character to be sent instead of a message sent to the user should be reproduced. In such cases, the operator defines an escape control character.

In the embodiment Two-way pager does not use ringing in the present invention. Instead, paging calls are made in which a single address codeword is used as a confirmation a transmission be interpreted by a pager. It is an alternative on the use of the REC parameter in the invitation control sequence ICS.

For POCSAG Pagers identify the function bits that are in the address codeword be used, i. Bits 20 and 21, the ICS, to which the pager has answered. The function bits are the least consistent with the two significant bits of the ICS [RefICS] parameter.

The Use of such calls is optional.

The Use of the command sequences described above in a paging system and how a pager should respond to the command sequences for implementation of two-way paging will be described below.

• i) Dringend gebetene: Dies sind erwartete Übertragungen von Pagern als Ergebnis einer Nachricht.
• ii) Nicht dringend gebetene: Dies sind unerwartete Übertragungen von Pagernbeispielsweise beim Registrieren vom Umhergehen, oder wenn der Benutzer um Information bittet.

The following applies:
Two types of pager transfers can be sent:

• i) Urgent: These are expected transfers of pagers as a result of a message.
• ii) Unsolicited: These are unexpected transfers of pagers, for example, when registering to walk or when the user asks for information.

pager can just one answer, after an invitation control sequence ICS or a quick invitation control sequence FICS has been received. The parameters in the control sequences are used to determine if and what type of answers allowed are. Except when not urgently asked answers invited, the ICS is used in conjunction with the RACS. The FICS is used by itself.

• i) Vorgabe Diese sind bereits im Zusammenhang mit der Beschreibung der 8 und 9 definiert worden.
• ii) Permanent Gelegentlich können Pager instruiert werden, verschiedene Rückantwortcodes für Antworten auf Nachrichten zu verwenden. Derartige Instruktionen werden typischerweise umhergehenden Pagern gegeben. Die RDACS sorgt dafür, dass Pager die Verwendung von Vorgabecodes wieder aufnehmen.
• iii) Provisorisch Nachrichten können Rückantwortcodes enthalten, die von Pagern nur für diese Nachricht verwendet werden sollen. Nachfolgende Antworten auf Nachrichten benutzen Vorgabe- oder permanente Codes.

Pagers can transmit a code of various codes in response to a message. The meaning of the respective codes is defined afterwards. Response codes fall into one of three categories:

• i) specification These are already in connection with the description of the 8th and 9 been defined.
• ii) Permanent Occasionally, pagers may be instructed to use different response codes for responses to messages. Such instructions are typically given to passing pagers. The RDACS ensures that pagers resume the use of default codes.
• iii) Temporarily messages may contain return codes that pagers should only use for this message. Subsequent responses to messages use default or permanent codes.

• 1) Das Einladen von Pagern sofort auf eine Nachricht zu antworten. Dies wird dadurch erreicht, dass die ICS und die RACS in derselben Nachricht gesendet werden, oder dadurch, dass die FICS gesendet wird. Im Allgemeinen würden nur einige Pager Antworten gleichzeitig übertragen.
• 2) Das Einladen von Pagern zusammen zu antworten. Dies wird dadurch erreicht, dass die RACS in einzelnen Nachrichten gesendet werden und dass danach die ICS als Gruppenanruf gesendet wird. Diese Technik ist erforderlich, wenn für Uplinkübertragungen und Downlinkübertragungen dieselbe Frequenz verwendet wird.

Operators can apply one or two basic strategies:

• 1) Inviting pagers to respond immediately to a message. This is accomplished by sending the ICS and RACS in the same message, or by sending the FICS. In general, only a few pagers would transmit answers at a time.
• 2) Inviting pagers to respond together. This is accomplished by sending the RACS in individual messages and then sending the ICS as a group call. This technique is required when the same frequency is used for uplink and downlink transmissions.

There are a total of 2 ¹⁸ sequences available for using pagers to transmit responses to messages. Depending on the phase step, up to 512 codes per sequence are available. This means that up to 2 ²⁷ codes are available for use.

These Codes can for one or for Two purposes are used - as occupied codes for single pagers, or as free codes for general use.

The Constant [N] and the parameter [Phase Step] (as described above described with the code generation) create a number of options. For the Phase step values 8 and 16 are these, as shown in Table 2.

Plate 2 Phases and Sequences

• 1) Niemals Sequenz- oder Phasenneuzuordnung verwenden und keine freien Sequenzen haben. Diese Strategie bedeutet, dass nur eine einzige Zweiwegnachricht gleichzeitig zu einem Pager gesendet werden kann.
• 2) Nur Phasenneuzuordnung verwenden. In diesem Fall würde eine feste Anzahl Pager sich die Phasen deren bestimmter Sequenz teilen. Wenn beispielsweise [N] = 4 ist und [Phase Step] = 8 ist, würden 16 Pager sich alle 256 Phasen derselben Sequenz teilen.
• 3) Immer die Sequenz- und Phasenneuzuordnung verwenden. In diesem Fall soll [N] höher gewählt werden und die freien Sequenzen sollen immer für Nachrichten verwendet werden.

Command sequences defined above allow codes (sequences and phases) to be mapped on a message basis. There are three strategies available:

• 1) Never use sequence or phase remapping and have no free sequences. This strategy means that only a single two-way message can be sent simultaneously to a pager.
• 2) Use only phase remapping. In this case, a fixed number of pagers would share the phases of their particular sequence. For example, if [N] = 4 and [Phase Step] = 8, 16 pagers would share all 256 phases of the same sequence.
• 3) Always use the sequence and phase remapping. In this case, [N] should be higher and the free sequences should always be used for messages.

It can several hybrids are used. It should be noted that it is supported when "roaming" is required, that pagers passing around their [Phase Step] Have reprogrammed parameters.

One Pager can transmit a sequence of a number of sequences, each one different Have meaning. To limit processing in the base station the ICS can do the transmission of pagers to a subset, by a suitable Use of [Type] parameters in ICS and RACS.

• ACK: Bestätigung. Dies informiert den Pagingnetzwerkcontroller, dass die Nachricht einwandfrei empfangen wurde.
• DISP: Wiedergegeben. Dies informiert den Pagingnetzwerkcontroller, dass die Nachricht einwandfrei empfangen und für den Benutzer wiedergegeben wurde.
• ANR: Antwort fertig. Dies informiert den Pagingnetzwerkcontroller, dass eine Benutzerantwort auf die Nachricht fertig ist.
• FLG: Jede beliebige Antwort fertig. Dies informiert den Pagingnetzwerkcontroller, dass eine Benutzerantwort auf eine beliebige Nachricht fertig ist.
• ANSn: Eine wirkliche Antwort auf die Nachricht, wobei n eine Zahl ist. Nicht dringend erbetene Übertragungen umfassen:
• REG: Registrierung
• DAT: Daten, wobei höhere Uplinkdatenraten verwendet werden.

Transmissions that are urged by a paging network controller include:

• ACK: confirmation. This informs the paging network controller that the message was received correctly.
• DISP: Played. This informs the paging network controller that the message has been properly received and rendered to the user.
• ANR: Answer finished. This informs the paging network controller that a user response to the message is ready.
• FLG: Any answer ready. This informs the paging network controller that a user response to any message is ready.
• ANSn: A real answer to the message, where n is a number. Non-urgent transmissions include:
• REG: registration
• DAT: data using higher uplink data rates.

The pseudo-random data sequence to be used by a pager is described above in connection with the description of FIG 8th and 9 been defined. However, it can be changed by receiving commands defined in Table 1. A pager should use response phases as follows: Phase: - ACK or REG message confirmation or registration Phase + Phase Step: - DISP message played Phase + 2 × Phase Step: - ANR or FLG answer done Phase + 3 × Phase Step: - ANS0 "None of these" Phase + 4 × Phase Step: - ANS1 user response 1 Phase + 5 × Phase Step: - ANS2 user response 2 Phase + (N-3) × Phase Step: - ANSN user response N where the default phase of a pager and the phase step are as defined above. The phase step can be changed by commands as defined in Table 1.

The following restrictions apply:
REG and FLG responses can not be sent in a provisional sequence or phase.

If More than just a message is sent to a pager, the answers requires the RACS [code] parameter, or TSACS and TPACS be used.

If a pager has finished answering for More than just a message, the answer is to the oldest message are given. The exception is when dismembered messages are sent and other rules apply.

The following rules must be used to determine if a response from the pager may be sent. Reference is made to the ICS, RACS and the FICS taken. If progressive elimination is to be applied, Also apply the rules that are subsequently related to a description of progressive elimination.

• Entweder alle der nachfolgenden Bedingungen: Der RACS [Type] Parameter gestattet Bestätigung. Der ICS [Type] Parameter gestattet Bestätigung, Der RACS [RefRACS] und der ICS [RefICS] Parameter sind identisch. Die ICS ist die erste ICS, die nach der RACS empfangen worden ist.
• Oder: Eine FICS wird gesendet.
• Außerdem gilt Folgendes: Die Nachricht ist empfangen worden und alle Fehler sind korrigiert. Die Nachricht ist weniger als ein Tag alt. DISP Antworten auf eine Nachricht können nur gesendet werden, wenn alle nachfolgenden Bedingungen erfüllt sind.

Acknowledgment responses ACK to a message can only be sent if the following conditions are met:

• Either all of the following conditions: The RACS [Type] parameter allows acknowledgment. The ICS [Type] parameter allows acknowledgment, The RACS [RefRACS] and the ICS [RefICS] parameters are identical. The ICS is the first ICS received after the RACS.
• Or: A FICS is sent.
• In addition, the following applies: The message has been received and all errors have been corrected. The message is less than a day old. DISP responses to a message can only be sent if all subsequent conditions are met.

The Message is for the user plays. It should be noted that this is a pager-dependent function is.

Of the RACS [Type] parameter allows reproduced answers. The ICS [Type] parameter allows reproduced answers.

Of the RACS [Time] parameter is greater than the ICS [Time] parameter. The message is less than 16 days old.

If a previous DISP transmission for the Message has been sent and has not been confirmed.

Not more than [R] DISP transmissions have been made to the message, where [R] by the operator is defined. For example, if R = 3, then only three DISP transmissions to be made on a message, being because of the progressive Elimination retransmissions not counted become.

The ANR, FLG and ANSn responses are used to transport user responses to a message. The use of it is as follows:
ANR: A user response is ready to be transmitted. This type of response provides the operator with the ability to determine if answers are ready before searching for them, reducing the processing load.
FLG: This answer is only used if more than one message has been sent to a pager that has responses. It indicates that a response is ready for any pending response.
ANSn: This is a real answer to a message.

• 1) Bitte um ANR Antworten, danach Bitte um ANSn Antworten. Dies soll verwendet werden, wenn eine große Anzahl Antworten antizipiert werden.
• 2) Bitte um FLG Antworten, danach Bitte um ANSn Antworten.
• 3) Nur Bitte um ANSn Antworten. Dies soll verwendet werden, wenn die Anzahl erwarteter Antworten gering ist.

This allows one of three strategies to be applied:

• 1) Ask for ANR answers, then ask for ANSn replies. This should be used when a large number of responses are anticipated.
• 2) Ask for FLG answers, then ask for ANSn replies.
• 3) Only request for ANSn answers. This should be used if the number of expected answers is low.

ANR responses to a message can only be sent if all the following conditions are met:
The user has a reply to the message. It should be noted that this is a pager-dependent function.

Of the RACS [Type] parameter allows user response.

Of the ICS [Type] parameter allows specific user response complete responses. The RACS [Time] parameter is greater than the ICS [Time] parameter.

The Message is less than 16 days old.

On this message has been made less than [R] ANR transmissions.

FLG responses can only be sent if all of the following conditions are met:
The user has a reply to every message. It should be noted that this is a pager-dependent function.

Of the RACS [Type] parameter allows user response.

Of the ICS [Type] parameter allows general user response complete responses. The RACS [Time] parameter is greater than the ICS [Time] parameter.

The Message is less than 16 days old.

Not more than [R] FLG transmissions have been made to the message.

ANSn responses to a message can only be sent if all subsequent conditions are fulfilled:
The user has selected this response to the message. It should be noted that this is a pager-dependent function.

Of the RACS [Type] parameter allows user response.

Of the ICS [Type] parameter allows user response.

Of the RACS [Time] parameter is greater than the ICS [Time] parameter. The message is less than 16 days old.

It were not more than [R] ANSn transfers on the message, where [R] is the same as for DISP answers.

Registration reactions REG can only be sent if the following conditions are met:
There is a need to send a REG command. (This is application-dependent).

Of the ICS [Type] parameter does not give urgently requested answers (Bit 5 is free).

The URN defined in the ICS [Type] parameter is less than or equal to 18 (<52 _h >).

The reply code used by the pager for registration shall be the default code used in the description of the 8th and 9 has been described, or the permanent code is by commands in the blackboard 1 modified. This code will continue to be modified as follows:
URN defines a mask based on b and c shift registers 118 respectively. 116 of the sequence generator ( 8th ) is to be applied. The mask should be "ANDed" with the values in the shift registers and the result will be in the shift registers 118 and 116 saved.

The The phase used by the pager is still unmodified. It Note that if URN = 0 then the sequence is also after as before unmodified.

The Using URN gives the operator the ability to identify pagers who want to register on a repeated basis. This avoids that base stations many thousands of return codes have to search.

• 1) Benutze Vorgabe- oder permanente Codes:
• 2) Benutze provisorische Codes.

Two way notification is not limited to personal calls. For two-way calls to a group of pagers, there are two techniques available:

• 1) Use default or permanent codes:
• 2) Use provisional codes.

Group calls using default or permanent codes is the simplest mechanism for sending group two-way messages. The following applies:
Group calls are received in a common RIC shared by all other pagers.

provisional Codes are not defined in the message.

pager respond to group two-way calls, such as personal calls.

Of the Pager does not need the difference between group RICs and personal ones Knowing RICs and every pager reacts with his unique Code.

• i) Es kann nur ein einziger derartiger Zweiweganruf gleichzeitig gesendet werden.
• ii) Die Anzahl Codes, die für Antworten verfügbar sind, ist begrenzt.

It should be noted that there are two limitations with this technique:

• i) Only one such two-way call can be sent simultaneously.
• ii) The number of codes available for responses is limited.

Group calls using provisional codes is a more complex mechanism for sending group calls, but the limits are overridden when using default or permanent codes. The following applies:
Each pager must have a common RIC, releasing the group call ID, and each pager must have a unique subaddress [2]. Group calls are defined as those using at least one proxy symbol.

All Group calls should contain a provisional sequence and phase, either by using the [code] parameter of the RACs or by using the TSACS and TPACS commands.

The phase used by a pager should be:
{[Phase step] × [C _N ] × [sub-address + phase]} MOD 2 ¹²

The sequence used by the pager should be:
{[Init b] [Init c] + [Phase Step] × [C _N ] × [sub-address + phase]} DIV 2 ¹² ) MOD 2 ¹⁸
Where [Phase Step] is, as previously described, and
[Init b] [Init c] and [Phase] is as defined in the [Code] parameter of the RACS or in the TSACS and TPACS.

[C _N ] defines the number of possible answers to the message and can be calculated as follows:
If the RACS [Type] parameter allows SCKs, r _ack = 1, otherwise r _ack = 0.
If the RACS [Type] parameter allows DISPs, r _disp = 1, otherwise r _disp = 0.
If the RACS [Type] parameter allows ANRs, r _anr = 1, otherwise r _anr = 0.
When r _anr = 1; if "Canned Dictionary" is used, r _ans = 256, otherwise r _ans = 1 + number of possible answers.
If r _anr = 0; r _ans = 0. CN = r ack + r disp + r anr + r ans

progressive Elimination is particularly applicable if recipient sites probably suffer from the near-far problem with CDMA transfers is associated. If in a distributed paging system with many recipient sites this problem is not considered essential, then this is Technique optional.

If Progressive elimination is not applied, the ICS [Slot] Parameter always be 0.

Progressive elimination is implemented as follows:
Several ICSs are sent as one row.
All pagers react to the first ICS.
A second ICS will be transmitted afterwards containing the [REC] parameter.
This informs pager if their reaction has been received.
Only pagers whose response has not been received again transmit in response to the second ICS.
A third and subsequent ICS can be sent, each containing the [REC] parameter.
Typically, the [Length] parameter is set low for the first ICS and increased for subsequent ICs in the series.

At the End of the response There may be some pagers whose reactions still are not from that Pagingsystem have been detected. The operator can have a maximum Specify the number of times that a message should be transmitted.

To avoid paging between different rows, the [RefICS] and [Slot] parameters in the ICS are used as follows:
The [RefICS] parameter is the same for each row and is incremented by one for the next row. When [RefICS] reaches <7F _h >, it should be reset to <20 _h >.

Of the Slot parameter is 0 for the first ICS in a row, and increased by 1 for each ICS in the series. He will only reset to 0, when the [RefICS] parameter increases.

The [REC] parameter is only available when [Slot] is not zero. For example, a series can be:
<7E _h ><30 _h >, <7E _h ><31 _h >, <7E _h ><32 _h >, <7E _h ><33 _h >

The next row will be:
<20E _h ><30 _h >, <20E _h ><31 _h >, <20E _h ><32 _h >, <20E _h ><33 _h >

The next:
<21E _h ><30 _h >, <21E _h ><31 _h >, <21E _h ><32 _h >, <21E _h ><33 _h >. Etc.

Of the ICS [REC] parameter is related to the RACS [ARB] parameter used and they are used to implement the progressive Elimination.

He is used by pagers that have a transmission in the previous one Send ICS to a progressive elimination suite to determine whether her transfer was received.

He contains a variable number of bits that identify pagers, their answer was received, with one bit identifying a pager.

Pagers determine which bit they are associated with as follows:
For calls to individual pagers, the bit number from the [ARB] parameter in the RACS, counting from zero, is uniquely defined. (For example, where [ARB] is 5, this is the same as the sixth bit).

For calls to a group of pagers, the bit number is the pager number in the group + n ₁ n ₂ , defined in the [ARB] parameter in the RACS.

The following rules apply:
If the bit is set to 1, then the pager should send a response.

If the bit is set to 0, a previous answer has been received and retransmission is not mandatory.

If the ICS [slot] parameter is zero, (there is no [REC] parameter), then the pager should send an answer.

Of the ICS [REC] parameter can be early ends and contain fewer bits than expected. Bits truncated by [REC] should have an assumed value 0.

Of the [ARB] value can have a time limit. This offers the possibility that he is for other pagers in later transmissions is used again. When a time limit is set (the RACS [TimeARB] parameter exists) then can progressive elimination be applied to the specified part.

It Note that if no time limit is specified, then the [ARB value for all progressive elimination sequences for responses to the message. A description will be given below as the control sequences and pager responses can be used.

to Facilitation of understanding These respective uses become progressive elimination except Considered.

12 Figure 4 is a timing diagram showing the paging system primary station transmitting an invitation control sequence ICS, the message being received by a single pager PG transmitting an acknowledgment ACK.

If the ACK is not received, the paging system can continue to repeat the message as determined by the operator.

There are times when the paging system wants to be notified when the message is played back to the user. This is in 12 shown. In some cases ACK and DISP responses can be made by the pager, as when a pager user does not immediately look at a message. In other cases, the DISP answer is just enough.

As in 13 an ACK is sent by the pager PG in response to a message with ICS. The paging system primary station requests to be informed when the message has been reproduced for the user by sending a "request for DISP" message, which may need to be repeated. Once the user has read the message, the pager transmits DISP.

It be noted that "request for DISP "means that one ICS is sent, with the [Type] parameter set to bits 1 and 5 Has. The ICS can be personalized or group message.

In In the case of messages requiring a response, the ANR, FLG, and ANSn responses are used on user responses to send a message.

• 1) Beantrage ANR Antworten, danach beantrage ANSn Antworten
• 2) Beantrage FLG Antworten, danach beantrage ANSn Antworten.
• 3) Beantrage nur ANSn Antworten.

This allows one of three strategies to be applied:

• 1) Apply for ANR replies, then request ANSn replies
• 2) Apply for FLG replies, then request ANSn replies.
• 3) Apply for ANSn answers only.

To the Minimize processing in the paging network controller PNC User responses to a message are given in two answers. In the first answer, the pager sends an "ANR", indicating to the PCN that an answer is available. The PNC sends after that another ICS to the pager requesting the answer. In reaction then the pager sends the user response to the message.

Of the PNC has to all possible Answers for wanted this message.

The signaling sequence between the paging system primary station and the pager PG is in 13 shown.

Short said, the paging system sends a message to the RACS and ICS contains to the pager. The pager confirmed receiving by sending ACK. The paging system requested an answer is sent by ANR after a time interval is repeated, wherein in this time interval the user receives the message reads and gives an answer. The answer ANR is transmitted and in response to the receipt, the paging system sends a request for ANSn, which is answered by the pager.

It be noted that "request for ANR "means that ICS is sent, with the [Type] parameter setting bits 2 and 5 Has. "Application for ANSm" means that one ICS has been sent, with the [Type] parameter bits 4 and 5 has set.

An alternative method of minimizing processing in the paging network controller PNC requires the pager, when sending the first response, to send an "FLG" indicating to the paging network controller that a response to any message is available. The base station then sends another ICS to the pager requesting the response. In response, the pager sends the user response to the message. This is in 15 shown in many views of the 14 except that instead the paging system transmits "Request for ANR" and the pager sends "ANR", the paging system sends "Request for FLG" and the pager sends "FLG".

The Base Station has been looking for all possible answers for all previous ones News searched.

It be noted that "request for FLG "means that one ICS has been sent, with the [Type] parameter bits 2 and 5 has set. The application for ANSn "means that one ICS has been sent, with the [Type] parameter bits 4 and 5 has set.

If the number of responses from pagers is low, the paging network controller can request responses directly without making an ANR or FLG request in the ICS, as in the 14 and 15 shown. Instead, the paging system sends "Request for ANSn", to which the pager responds by sending ANSn.

It be noted that "request for ANSn "means that one ICS has been sent, with the [Type] parameter bits 4 and 5 has set.

The Base station must be all possible Responses from all pagers for search all previous messages.

Registration allows pagers to register in a paging system. There are two options - the first one is the paging system informing about the pager's location. The second is that a service can be requested. The following is an example:
The user requests a service through a registration call with memory. This request may be sent in response to the paging system sending a generic ICS requesting non-urgent responses.

A Message to the pager includes EACS, which describes available services.

Of the User selects an answer (for example traffic news). Message to the pager that creates information.

• i. Alle Fragmente außer dem letzten können als eine Einweg- oder als eine Zweiwegnachricht gesendet werden. Das letzte Fragment muss eine Zweiwegnachricht sein.
• ii. Bestätigung eines Zweiwegfragmentes soll derart interpretiert werden, als bedeute es, dass alle Fragmente bis einschließlich das Fragment erfolgreich empfangen wurden.
• iii. Alle Zweiwegfragmente außer dem letzten sollen nur ACK Antworten verwenden. Das letzte Fragment kann ACK, DISP, ANR, FLG und ANSn Antworten verwenden, was für die ganze Nachricht gilt.
• iv. Für fragmentierte Nachrichten mit eingebetteten Antworten soll die Nummerierung der Antworten und die Möglichkeit, dass der Benutzer eine Antwort selektiert, nur erlaubt sein, nachdem alle Fragmente erfolgreich empfangen und die Nachricht rekonstruiert worden sind.

Sending long messages, such as a series of fragments in automatic request logs ARQ can be applied. For example, an ACK can be used to confirm receipt of multiple fragments. Rules for sending two-way fragmented messages should be as follows:

• i. All fragments except the last can be sent as a one-way or two-way message. The last fragment must be a two-way message.
• ii. Confirmation of a two-way fragment should be interpreted as meaning that all fragments up to and including the fragment have been successfully received.
• iii. All two-way fragments except the last should only use ACK responses. The last fragment can use ACK, DISP, ANR, FLG and ANSn responses, which is true for the whole message.
• iv. For fragmented messages with embedded responses, the numbering of responses and the possibility that the user selects a response should only be allowed after all fragments have been successfully received and the message has been reconstructed.

Operators can Use these rules to implement multiple ARQ schemes without that the pager requests to know which protocol is being used. The following subsections describe how some standard ARQ schemes could be implemented.

In In the event that a single ARQ is requested for the whole message the paging system sends all fragments except the last one as a one-way message. A successful confirmation the last fragment means that all other fragments succeed were received.

If the message is not confirmed is, then the whole message should be retransmitted. It is however noticed that information signal should be possible that a pager rebuild a message from fragments of different transmissions. This is a very simple, albeit inefficient scheme - where the main purpose is delays of system messages for reduce other users.

A alternative approach is called a stop and wait, with each fragment as one Two-way message is sent. The paging system is waiting for you successful confirmation, before the next fragment is sent.

In another approach each fragment is sent as a two-way message without going on a successful confirmation the previous fragment is serviced. Every fragment becomes another reply code require. If, at the request of the pagers the last fragment not confirmed, should the system all the fragments behind the one that was still confirmed retransmitted.

In another approach each fragment is sent as a two-way message without going on a successful confirmation the previous fragment is serviced. Every fragment becomes another reply code require. If requested by the pager the last fragment not confirmed, should the system only the one fragment behind the one that was confirmed retransmitted.

Combinations of these different approaches can be applied. For example the stopping and waiting are combined with the simple ARQ, where each N. fragment is a two-way message.

Out the reading of the present description the skilled person will come to other modifications. Such modifications can Other characteristics concern those in the field of design, manufacture and manufacture the application of messaging systems or parts thereof already known and instead of or in addition to the features already described here are used.

Industrial applicability

Zweiwegübertragungssysteme for example Rear answering-paging systems.

Text in the drawing

8th

• 12 bit sequence generator
• 12 bit XOR masks
• 12-bit shift register
• switch

10

• Synchronization code word
• invitation message
• Data not transferred need to be
• System Wear
• pager transmission Pager sequence start

11

• system transfer
• Start of the synchronization code word
• pager transmission
• Start of the chip sequence

12

• Time message is received ACK from the pager

13

• Message with ICS
• Time
• Message is received ACK from the pager
• formal request for DISP
• User reads message
• DISP from PG

14

• Message about PG with RACS and ICS
• Time
• Message received ACK from the PG
• formal request for ANR
• User reads message and gives an answer
• ANR from the PG
• formal request for ANSn
• ANSn from the PG
• Message about PG with RACS and ICS
• Time
• Message received ACK from the PG
• formal request for FLG
• User reads message and gives an answer
• formal request for FLG
• FLG from the PG
• formal request for ANSn
• ANSn from the PG

Claims (8)

Method for operating a message transmission system with at least one primary station ( 10 . 14 . 16 . 22 ), which makes transmissions via a downlink, and a number of secondary stations ( eighteen . 20 ), which makes transmissions over an uplink, with each of the secondary stations ( eighteen . 20 ) has its own address transmitted as part of a downlink message, characterized in that each uplink transmission has a pseudo-random data sequence generated by providing at least the address associated with the secondary station to an n-bit Follower generator ( 116 . 118 ). Message transmission system with at least one primary station ( 10 . 14 . 16 . 20 ) with means ( 14 . 16 ) for carrying out transmissions via a downlink and with a number of secondary stations ( eighteen . 20 ) with means ( 72 . 90 ) for making transmissions over an uplink, each of the secondary stations ( eighteen . 20 ) has its own address, which is transmitted as part of a downlink message, characterized in that the means ( 72 . 90 for generating transmissions over the uplink, responses to messages, each of said responses comprising a pseudo-random data sequence generated by providing at least the address associated with the secondary station to an n-bit sequence generator ( 116 . 118 ). System according to claim 2, characterized in that the means ( 72 . 90 ) are provided for performing transmissions over the uplink to select the pseudo-random data sequence based on the response type. System according to claim 2, characterized in that the means ( 14 . 16 ) are arranged to carry out transmissions over the downlink, a group message to a number of said secondary stations ( eighteen . 20 ) and that the funds ( 72 . 90 ) are arranged to perform transmissions over the uplink to produce in response a unique pseudo-random data sequence. System according to claim 2, 3 or 4, characterized in that at least one of the secondary stations ( eighteen . 20 ) Storage means ( 76 ) for storing a number of received messages and means ( 72 ) for generating a unique response to each of said number of messages. System according to one of claims 2 to 4, characterized in that the primary station ( 10 . 14 . 16 . 22 ) Medium ( 14 ) has around the mentioned secondary stations ( eighteen . 20 ) to request that their answers be translated into 14 ) are requested to repeat the request and in this way to confirm receipt of those responses which have been successfully received and that those of said secondary stations ( eighteen . 20 ) receiving an acknowledgment of their response are intended to refrain from answering the repeated request. Secondary station ( eighteen . 20 ) for use in a communication system, wherein at least one primary station ( 10 . 14 . 16 . 22 ) Messages via a downlink to addressed secondary stations ( eighteen . 20 ), each secondary station having means ( 72 . 90 ) for performing transmissions over an uplink, characterized in that the means ( 72 . 80 ) for performing transmissions over an uplink to transmit in response to a received message a pseudo-random data sequence generated by providing at least one address associated with the secondary station to an n-bit Follower generator ( 116 . 118 ). Secondary station according to claim 7, characterized in that in response to a primary station ( 10 . 14 . 16 . 22 ) sending a group message, the means ( 72 . 90 ) are arranged to perform transmissions over the uplink to produce a unique pseudo-random data sequence in response.